Snowflake: Add implementation for CREATE TASK statement (sqlfluff#1597)

src/sqlfluff/dialects/dialect_snowflake.py

@@ -124,6 +124,8 @@
         "TERSE",
         "TABULAR",
         "UNSET",
+        "USER_TASK_TIMEOUT_MS",
+        "USER_TASK_MANAGED_INITIAL_WAREHOUSE_SIZE",
         "WAIT_FOR_COMPLETION",
         "WAREHOUSE_SIZE",
     ]
@@ -436,6 +438,7 @@ class StatementSegment(ansi_dialect.get_segment("StatementSegment")):  # type: i
         insert=[
             Ref("UseStatementSegment"),
             Ref("CreateStatementSegment"),
+            Ref("CreateTaskSegment"),
             Ref("CreateCloneStatementSegment"),
             Ref("ShowStatementSegment"),
             Ref("AlterUserSegment"),
@@ -1341,6 +1344,104 @@ class CreateTableStatementSegment(BaseSegment):
     )
 
 
+@snowflake_dialect.segment()
+class CreateTaskSegment(BaseSegment):
+    """A snowflake `CREATE TASK` statement.
+
+    ```
+    CREATE [ OR REPLACE ] TASK [ IF NOT EXISTS ] <name>
+        [ WAREHOUSE = <string> ]
+        [ SCHEDULE = '{ <num> MINUTE | USING CRON <expr> <time_zone> }' ]
+        [ ALLOW_OVERLAPPING_EXECUTION = TRUE | FALSE ]
+        [ <session_parameter> = <value> [ , <session_parameter> = <value> ... ] ]
+        [ USER_TASK_TIMEOUT_MS = <num> ]
+        [ USER_TASK_MANAGED_INITIAL_WAREHOUSE_SIZE = <string> ]
+        [ COPY GRANTS ]
+        [ COMMENT = '<string_literal>' ]
+        [ AFTER <string> ]
+    [ WHEN <boolean_expr> ]
+    AS
+        <sql>
+    ```
+
+    CAUTION: The `WHEN` clause is currently not implemented.
+
+    https://docs.snowflake.com/en/sql-reference/sql/create-task.html
+    """
+
+    type = "create_task_statement"
+
+    match_grammar = Sequence(
+        "CREATE",
+        Sequence("OR", "REPLACE", optional=True),
+        "TASK",
+        Sequence("IF", "NOT", "EXISTS", optional=True),
+        Ref("ObjectReferenceSegment"),
+        Indent,
+        Sequence(
+            "WAREHOUSE",
+            Ref("EqualsSegment"),
+            Ref("ObjectReferenceSegment"),
+            optional=True,
+        ),
+        Sequence(
+            "SCHEDULE",
+            Ref("EqualsSegment"),
+            Ref("QuotedLiteralSegment"),
+            optional=True,
+        ),
+        Sequence(
+            "ALLOW_OVERLAPPING_EXECUTION",
+            Ref("EqualsSegment"),
+            Ref("BooleanLiteralGrammar"),
+            optional=True,
+        ),
+        Delimited(
+            Sequence(
+                Ref("ParameterNameSegment"),
+                Ref("EqualsSegment"),
+                OneOf(
+                    Ref("BooleanLiteralGrammar"),
+                    Ref("QuotedLiteralSegment"),
+                    Ref("NumericLiteralSegment"),
+                ),
+            ),
+            delimiter=Ref("CommaSegment"),
+            optional=True
+        ),
+        Sequence(
+            "USER_TASK_TIMEOUT_MS",
+            Ref("EqualsSegment"),
+            Ref("NumericLiteralSegment"),
+            optional=True,
+        ),
+        Sequence(
+            "USER_TASK_MANAGED_INITIAL_WAREHOUSE_SIZE",
+            Ref("EqualsSegment"),
+            Ref("QuotedLiteralSegment"),
+            optional=True,
+        ),
+        Sequence(
+            "COPY",
+            "GRANTS",
+            optional=True,
+        ),
+        Ref("CreateStatementCommentSegment", optional=True),
+        Sequence(
+            "AFTER",
+            Ref("QuotedLiteralSegment"),
+            optional=True,
+        ),
+        Dedent,
+        Sequence(
+            Ref.keyword("AS"),
+            Indent,
+            Ref("StatementSegment"),
+            Dedent,
+        ),
+    )
+
+
 @snowflake_dialect.segment()
 class CreateStatementSegment(BaseSegment):
     """A snowflake `CREATE` statement.
@@ -1378,7 +1479,6 @@ class CreateStatementSegment(BaseSegment):
             Sequence("FILE", "FORMAT"),
             "STAGE",
             "STREAM",
-            "TASK",
         ),
         Sequence("IF", "NOT", "EXISTS", optional=True),
         Ref("ObjectReferenceSegment"),

test/fixtures/parser/snowflake/snowflake_create_task.sql

@@ -0,0 +1,6 @@
+CREATE TASK t1
+    SCHEDULE = 'USING CRON 0 9-17 * * SUN America/Los_Angeles'
+    TIMESTAMP_INPUT_FORMAT = 'YYYY-MM-DD HH24'
+    USER_TASK_MANAGED_INITIAL_WAREHOUSE_SIZE = 'XSMALL'
+AS
+    INSERT INTO mytable(ts) VALUES(1);

test/fixtures/parser/snowflake/snowflake_create_task.yml

@@ -0,0 +1,41 @@
+# YML test files are auto-generated from SQL files and should not be edited by
+# hand. To help enforce this, the "hash" field in the file must match a hash
+# computed by SQLFluff when running the tests. Please run
+# `python test/generate_parse_fixture_yml.py`  to generate them after adding or
+# altering SQL files.
+_hash: af2323a0483bae83a81490bc28c4d8acd8b0c793aaa661b9dc0ed6d2d85fa7de
+file:
+  statement:
+    create_task_statement:
+    - keyword: CREATE
+    - keyword: TASK
+    - object_reference:
+        identifier: t1
+    - keyword: SCHEDULE
+    - comparison_operator: '='
+    - literal: "'USING CRON 0 9-17 * * SUN America/Los_Angeles'"
+    - parameter: TIMESTAMP_INPUT_FORMAT
+    - comparison_operator: '='
+    - literal: "'YYYY-MM-DD HH24'"
+    - keyword: USER_TASK_MANAGED_INITIAL_WAREHOUSE_SIZE
+    - comparison_operator: '='
+    - literal: "'XSMALL'"
+    - keyword: AS
+    - statement:
+        insert_statement:
+        - keyword: INSERT
+        - keyword: INTO
+        - table_reference:
+            identifier: mytable
+        - bracketed:
+            start_bracket: (
+            column_reference:
+              identifier: ts
+            end_bracket: )
+        - values_clause:
+            keyword: VALUES
+            bracketed:
+              start_bracket: (
+              literal: '1'
+              end_bracket: )
+  statement_terminator: ;

test/fixtures/parser/snowflake/snowflake_create_task_all.sql

@@ -0,0 +1,12 @@
+CREATE OR REPLACE TASK IF NOT EXISTS t1
+    WAREHOUSE = mywh
+    SCHEDULE = 'USING CRON 0 9-17 * * SUN America/Los_Angeles'
+    ALLOW_OVERLAPPING_EXECUTION = TRUE
+    TIMESTAMP_INPUT_FORMAT = 'YYYY-MM-DD HH24'
+    USER_TASK_TIMEOUT_MS = 25
+    USER_TASK_MANAGED_INITIAL_WAREHOUSE_SIZE = 'XSMALL'
+    COPY GRANTS
+    COMMENT = 'Hello world'
+    AFTER 'dependency_task'
+AS
+    INSERT INTO mytable(ts) VALUES(1);

test/fixtures/parser/snowflake/snowflake_create_task_all.yml

@@ -0,0 +1,56 @@
+# YML test files are auto-generated from SQL files and should not be edited by
+# hand. To help enforce this, the "hash" field in the file must match a hash
+# computed by SQLFluff when running the tests. Please run
+# `python test/generate_parse_fixture_yml.py`  to generate them after adding or
+# altering SQL files.
+_hash: d7c9c725318a322009d331c30dba49c4ed9483b71e832b04923f79a61bb8d703
+file:
+  statement:
+    unparsable:
+    - raw: CREATE
+    - raw: OR
+    - raw: REPLACE
+    - raw: TASK
+    - raw: IF
+    - raw: NOT
+    - raw: EXISTS
+    - raw: t1
+    - raw: WAREHOUSE
+    - raw: '='
+    - raw: mywh
+    - raw: SCHEDULE
+    - raw: '='
+    - raw: "'USING CRON 0 9-17 * * SUN America/Los_Angeles'"
+    - raw: ALLOW_OVERLAPPING_EXECUTION
+    - raw: '='
+    - raw: 'TRUE'
+    - raw: TIMESTAMP_INPUT_FORMAT
+    - raw: '='
+    - raw: "'YYYY-MM-DD HH24'"
+    - raw: USER_TASK_TIMEOUT_MS
+    - raw: '='
+    - raw: '25'
+    - raw: USER_TASK_MANAGED_INITIAL_WAREHOUSE_SIZE
+    - raw: '='
+    - raw: "'XSMALL'"
+    - raw: COPY
+    - raw: GRANTS
+    - raw: COMMENT
+    - raw: '='
+    - raw: "'Hello world'"
+    - raw: AFTER
+    - raw: "'dependency_task'"
+    - raw: AS
+    - raw: INSERT
+    - raw: INTO
+    - raw: mytable
+    - bracketed:
+        start_bracket: (
+        raw: ts
+        end_bracket: )
+    - raw: VALUES
+    - bracketed:
+        start_bracket: (
+        raw: '1'
+        end_bracket: )
+  statement_terminator: ;

test/fixtures/parser/snowflake/snowflake_create_task_minimal.sql

@@ -0,0 +1,3 @@
+CREATE TASK t1
+AS
+    INSERT INTO mytable(ts) VALUES(1);

test/fixtures/parser/snowflake/snowflake_create_task_minimal.yml

@@ -0,0 +1,32 @@
+# YML test files are auto-generated from SQL files and should not be edited by
+# hand. To help enforce this, the "hash" field in the file must match a hash
+# computed by SQLFluff when running the tests. Please run
+# `python test/generate_parse_fixture_yml.py`  to generate them after adding or
+# altering SQL files.
+_hash: 5e7d90046023eb14b11e0b6ee84b48e2160de04eae5298e041dbf4de00598a2c
+file:
+  statement:
+    create_task_statement:
+    - keyword: CREATE
+    - keyword: TASK
+    - object_reference:
+        identifier: t1
+    - keyword: AS
+    - statement:
+        insert_statement:
+        - keyword: INSERT
+        - keyword: INTO
+        - table_reference:
+            identifier: mytable
+        - bracketed:
+            start_bracket: (
+            column_reference:
+              identifier: ts
+            end_bracket: )
+        - values_clause:
+            keyword: VALUES
+            bracketed:
+              start_bracket: (
+              literal: '1'
+              end_bracket: )
+  statement_terminator: ;